The high-speed rotary handpiece is used for drilling, cutting, and grinding in modern dental treatment. Emergence of HIV and AIDS has highlighted deficiencies in the current handpiece design, bringing recognition of its potential role in the transmission of infectious diseases. Current pneumatic handpieces are based on 50-year-old technology, predating popular concern over controlling cross-infection. Recent emphasis on this potential has been the impetus for new sterilization guidelines within the industry, but sterilization has introduced additional problems and has not eliminated the sources of concern. Nationally, the majority of dentists still do not sterilize their handpieces between patients. The goal of Phase I is to develop and show the feasibility of a new, sanitary, high-speed dental handpiece concept. One approach to be considered is the promising idea of the exhaust vacuum air turbine. This new handpiece concept provides several benefits in the area of cross- infection control, and has never before been evaluated. The result of this project will be a dental handpiece with significantly improved infection- transmission control characteristics, which could increase the safety of dental professionals and their patients and have immediate commercial application.